This mouse is a model of LIS1 dysfunction which presents a complete deletion of the LisH domain (Cahana et al. 2001); this LIS1 mutation is similar to that of a lissencephaly patient with an in-frame N-terminal deletion (Fogli et al. 1999), but it is different from the mutations of the Lis1 ± mouse described by Hirotsune et al. (1998); the developmental alterations detected in the Lis1/sLis1 and Lis1 ± models are also different (Cahana et al. 2001; Hirotsune et al. 1998). Here, PAFAH1B1 is linked to Lissencephaly.